Currently, in many internal combustion engines an electronic controller is used to control the air fuel mixture delivered to a combustion chamber of a cylinder of the engine, and to produce a timed ignition signal in response to sensed engine parameters to ignite the mixture in engines that are spark ignited. Generally, in a spark ignited engine, the ignition signal is delivered to a spark plug which is disposed centrally in the combustion chamber, and a flame is produced when the spark ignites the air fuel mixture.
A combustion sensor, which can be an ion probe, optical device, thermocouple, or like device, is typically also located in the combustion chamber. Examples of conventional combustion sensors and systems are shown in Earleson et al., U.S. Pat. No. 5,036,669, issued Aug. 6, 1991; Maddock et al., U.S. Pat. No. 5,041,980, issued Aug. 20, 1991; McCombie, U.S. Pat. No. 5,392,641, issued Feb. 28, 1995; and Wood, UK patent application GB 2282221, published Mar. 29, 1995. In operation, a combustion sensor typically produces a combustion signal in response to the presence of a predetermined combustion condition in the combustion chamber, such as, in the case of an ion probe, the flame propagating past the ion probe. If the flame is not detected by the combustion sensor, a combustion signal is not produced or delivered to the electronic controller. In the absence of the combustion signal, the electronic controller determines that the cylinder is "dead", that is, for some reason or another the combustion condition is not occurring in the combustion chamber. The electronic controller will then proceed to cutout the affected cylinder, typically by terminating fuel delivery to the cylinder.
A problem that can occur, however, is that the electronic controller can cutout a cylinder because no combustion signal is received from the combustion sensor for that cylinder, even when combustion is actually occurring in the cylinder, because there is a problem with the combustion sensor feedback system.
Accordingly, the present invention is directed to overcoming one or more of the problems as set forth above.